Early Diagnosis Of Invasive Candidiasis Research Articles

Molecular detection of Candida species from hospitalized patients’ specimens

Objective To identify the most frequent Candida species in specimens from patients hospitalized in different medical centers of Mexico City, with suspected fungal infection. Methods Specimens were grown on Sabouraud dextrose agar at 28°C for 72 h. In addition, DNA was extracted. Isolates were grown on CHROMagar Candida™, at 37°C for 48 h. The molecular identification was performed by polymerase chain reaction (PCR) using primers specific for four species. Results Eighty one specimens were processed and included: bronchial lavage, pleural, cerebrospinal, peritoneal, ascites and bile fluids; blood, sputum, bone marrow, oro-tracheal cannula and ganglion. By culture, 30 samples (37%) were positive, and by PCR, 41 (50.6%). By PCR, the frequency of species was: Candida albicans 82.9%, Candida tropicalis 31.7%, Candida glabrata 24.4%, and Candida parapsilosis 4.9%. In 34.1% of specimens a species mixture was detected suggesting a co-infection: Two species in five specimens (C. albicans-C tropicalis and C. albicans-C glabrata), and three species in three specimens (C. albicans-C. glabrata-C. tropicalis). Conclusions The PCR is an useful tool for detection the most common Candida species causing infection in hospitalized patients, it avoids the requirement of culture weather we start from clinical specimen and it favors the early diagnosis of invasive candidiasis.

Biomarker-guided antifungal stewardship policies for patients with invasive candidiasis.

Invasive fungal infections (IFIs) are among the life-threatening issues in patients with impaired immune system. High administration of antifungals in these patients imposes a heavy economic burden on the national health system. In addition, despite the usually expensive antifungal regimens, the mortality rate due to fungal infections is still high, resulting in the loss of hundreds of lives per year. Survival rate is an indicator of the success of national healthcare policies. Early diagnosis of IFI is critical because any delays may be fatal. The weakness of the old-fashioned culture-based diagnostic methods lies in their time-consuming laboratory procedures. To overcome this problem, several diagnostic approaches have been developed to facilitate the early diagnosis of invasive candidiasis as the most prevalent IFI. These methods are based on the detection of serologic and molecular footprints. However, nowadays, antibiotic resistance and proper and cost-effective use of antibiotics are given special attention in national healthcare policies. The instructions for controlling these indices have been collected under the name of antibiotic stewardship. The present review study was targeted toward providing insight into novel diagnostic biomarkers and antifungal stewardship programs. The simultaneous investigation of these two issues facilitates the achievement of a novel health policy for the treatment of systemic candidiasis in immunocompromised patients.

Prospective evaluation of lymphocyte subtyping for the diagnosis of invasive candidiasis in non-neutropenic critically ill patients

ObjectivesThis study aimed to investigate the distinguishing ability of lymphocyte subtyping for Invasive candidiasis (IC) diagnosis and prognosis in non-neutropenic critically ill patients. MethodsWe assessed the quantitative changes in key parameters of lymphocyte subtyping at the onset of clinical signs of infection in non-neutropenic critically ill patients and their potential influence on diagnosis and outcome of IC. The primary outcome was 28-day mortality. ResultsAmong the 182 consecutive critically ill patients, 22 (12.1%) were in the IC group. The CD28+CD8+ T-cell counts (AUC 0.863, 95%CI 0.804–0.909, P<0.001) had greater diagnostic value for IC than other parameters had. Adding CD28+CD8+ T to Candida score significantly improved the predictive value of Candida score (P=0.039). Multivariate logistic regression analysis identified CD28+CD8+ T-cell counts≤78 cells/mm3 (OR 24.544, 95%CI 6.461–93.236, P<0.001) as an independent predictor for IC diagnosis. CD28+CD8+ T-cell counts could also predict 28-day mortality. Kaplan–Meier survival analysis provided evidence that CD28+CD8+ T-cell count <144cells/mm3 (log-rank test; P=0.03) were associated with lower survival probabilities. ConclusionsCD28+CD8+ T-cell counts play an important role in early diagnosis of IC. Low counts are associated with early mortality in non-neutropenic critically ill patients. These results suggest the potential usefulness of measuring CD28+CD8+ T-cell lymphocyte levels in the early recognition and diagnosis of IC. Trial registrationChiCTR-ROC-17010750. Registered 28 February 2017.

Invasive candidiasis.

Invasive candidiasis is an important health-care-associated fungal infection that can be caused by several Candida spp.; the most common species is Candida albicans, but the prevalence of these organisms varies considerably depending on geographical location. The spectrum of disease of invasive candidiasis ranges from minimally symptomatic candidaemia to fulminant sepsis with an associated mortality exceeding 70%. Candida spp. are common commensal organisms in the skin and gut microbiota, and disruptions in the cutaneous and gastrointestinal barriers (for example, owing to gastrointestinal perforation) promote invasive disease. A deeper understanding of specific Candida spp. virulence factors, host immune response and host susceptibility at the genetic level has led to key insights into the development of early intervention strategies and vaccine candidates. The early diagnosis of invasive candidiasis is challenging but key to the effective management, and the development of rapid molecular diagnostics could improve the ability to intervene rapidly and potentially reduce mortality. First-line drugs, including echinocandins and azoles, are effective, but the emergence of antifungal resistance, especially among Candida glabrata, is a matter of concern and underscores the need to administer antifungal medications in a judicious manner, avoiding overuse when possible. A newly described pathogen, Candida auris, is an emerging multidrug-resistant organism that poses a global threat.

Experience with β-D-Glucan Assay in the Management of Critically ill Patients with High Risk of Invasive Candidiasis: An Observational Study.

Background:The (1,3)-β-D-glucan assay (BDG) is recommended for the early diagnosis of invasive candidiasis (IC).Methods:Records of 154 critically ill adults with suspected IC, on whom BDG was done, were analyzed. Patients were divided into three groups: Group A (confirmed IC), Group B (alternative diagnosis or cause of severe sepsis), and Group C (high candidal score and positive BDG [>80 pg/mL] but without a confirmed diagnosis of IC).Results:Mean BDG levels were significantly higher in Group A (n = 32) as compared to Group B (n = 60) and Group C (n = 62) (448.75 ± 88.30 vs. 144.46 ± 82.49 vs. 292.90 ± 137.0 pg/mL; P < 0.001). Discontinuation of empiric antifungal therapy based on a value <80 resulted in cost savings of 14,000 INR per day per patient.Conclusion:A BDG value of <80 pg/ml facilitates early discontinuation of empirical antifungal therapy, with considerable cost savings.

Molecular detection of candida species from hospitalized patient’s specimens.

To identify the most frequent Candida species in specimens from patients hospitalized in different medical centers of Mexico City, with suspected fungal infection. Specimens were grown on Sabouraud dextrose agar at 28°C for 72 h. In addition, DNA was extracted. Isolates were grown on CHROMagar Candida™, at 37°C for 48 h. The molecular identification was performed by polymerase chain reaction (PCR) using primers specific for four species. Eighty one specimens were processed and included: bronchial lavage, pleural, cerebrospinal, peritoneal, ascites and bile fluids; blood, sputum, bone marrow, oro-tracheal cannula and ganglion. By culture, 30 samples (37%) were positive, and by PCR, 41 (50.6%). By PCR, the frequency of species was: Candida albicans 82.9%, Candida tropicalis 31.7%, Candida glabrata 24.4%, and Candida parapsilosis 4.9%. In 34.1% of specimens a species mixture was detected suggesting a co-infection: Two species in five specimens (C. albicans-C tropicalis and C. albicans-C glabrata), and three species in three specimens (C. albicans-C. glabrata-C. tropicalis). The PCR is an useful tool for detection the most common Candida species causing infection in hospitalized patients, it avoids the requirement of culture weather we start from clinical specimen and it favors the early diagnosis of invasive candidiasis.

Experience with β-d-Glucan Assay for Diagnosis of Invasive Candidiasis in ICU Patients: Pilot Study from India

Backgroundβ-d-Glucan assay (BDG) has been recently introduced in India and is recommended for the early diagnosis of invasive candidiasis (IC), but there are a number of factors (eg β-lactam antibiotics, immunoglobulin and albumin infusions, bacteremia and surgical mesh) which may falsely elevate BDG levels.MethodsThis was a retrospective, observational study done in the 23 bedded multi-disciplinary ICU of a tertiary care hospital in South India. Case records of adult (> 18 years) non-neutropenic patients having severe sepsis or shock with ≥ 1 risk factor for IC were analyzed. As a standard practice, BDG assay was sent and effective antifungals were started on the day of suspicion of IC. All neutropenic, immunocompromised patients, those already on antifungal and those who were diagnosed with other invasive fungal infections were excluded from the study. FDA approved Fungitell assay was used to measure serum BDG levels (pg/mL).ResultsPatients were divided into 3 groups. Group A (n = 16) comprised of patients in whom diagnosis of IC was confirmed (blood culture or another sterile site grew candida). Group B (n = 30) comprised of patients in whom alternative diagnosis of severe sepsis or septic shock was found or they did not improve after administration of antifungals. Group C (n = 31) comprised of those patients in whom neither diagnosis of IC was confirmed nor an alternative explanation was found but they improved clinically on giving antifungal therapy. Mean BDG levels was significantly higher in Group A as compared with Group B and Group C (448.75 ± 88.30 vs 144.46 ± 82.49 vs 292.90 ± 137.0 pg/mL; P < 0.001). The mean value of the BDG was higher than the accepted cutoff of 80 pg/mL in all three groups (Figure 1). The use of agents which cause false elevation of BDG was significantly higher in Group B as compared with Group A (P = 0.02).ConclusionA BDG assay cutoff of 80 pg/mL leads to a higher number of false positive results in ICU patients, where false positive factors are unavoidable. The results of this study suggest that a higher cutoff of at least 144 pg/mL will be more specific for IC, although this may need further validation with larger trials.Figure 1:Mean BDG values in various groupsDisclosures All authors: No reported disclosures.

Evaluation on the basis of Candida Score in Critical Patients

The finding of the present study of 60 cases of candidal infection in critically ill patients has been evaluated with scoring system. However appropriate antifungal T/t is essential for the control of invasive candida infection. Early diagnosis of invasive candidiasis remains a challenge & to start empirical therapy in critical patient is poorly defined. To come over this problem one scoring system i.e;Candida score could be very helping hand for the treating physician to differentiate patients who could benefit from early antifungal T/t from those for whom invasive candidiasis is highly improbable. This present study in 60 patient evaluated the performance of this score in a cohort of critical patients.

Comparative Analysis of Denaturing Gradient Gel Electrophoresis and Temporal Temperature Gradient Gel Electrophoresis Profiles as a Tool for the Differentiation of Candida Species.

Background:Candida species are usually opportunistic organisms that cause acute to chronic infections when conditions in the host are favorable. Accurate identification of Candida species is an essential pre-requisite for improved therapeutic strategy. Identification of Candida species by conventional methods is time-consuming with low sensitivity, yet molecular approaches have provided an alternative way for early diagnosis of invasive candidiasis. Denaturing gradient gel electrophoresis (DGGE) and temporal temperature gradient gel electrophoresis (TTGE) are polymerase chain reaction (PCR)-based approaches that are used for studying the community structure of microorganisms. By using these methods, simultaneous identification of multiple yeast species will be possible and reliable results will be obtained quickly.Objectives:In this study, DGGE and TTGE methods were set up and evaluated for the detection of different Candida species, and their results were compared.Materials and Methods:Five different Candida species were cultured on potato dextrose agar medium for 24 hours. Next, total DNA was extracted by the phenol-chloroform method. Two sets of primers, ITS3-GC/ITS4 and NL1-GC/LS2 were applied to amplify the desired regions. The amplified fragments were then used to analyze DGGE and TTGE profiles.Results:The results showed that NL1-GC/LS2 primer set could yield species-specific amplicons, which were well distinguished and allowed better species discrimination than that generated by the ITS3-GC/ITS4 primer set, in both DGGE and TTGE profiles. All five Candida species were discriminated by DGGE and TTGE using the NL1-GC/LS2 primer set.Conclusions:Comparison of DGGE and TTGE profiles obtained from NL1-GC/LS2 amplicons exhibited the same patterns. Although both DGGE and TTGE techniques are capable of detecting Candida species, TTGE is recommended because of easier performance and lower costs.

Evaluation of "Candida score" in critically ill patients: a prospective, multicenter, observational, cohort study

IntroductionAlthough prompt initiation of appropriate antifungal therapy is essential for the control of invasive Candida infections and an improvement of prognosis, early diagnosis of invasive candidiasis remains a challenge and criteria for starting empirical antifungal therapy in ICU patients are poorly defined. Some scoring systems, such as the "Candida score" could help physicians to differentiate patients who could benefit from early antifungal treatment from those for whom invasive candidiasis is highly improbable. This study evaluated the performance of this score in a cohort of critically ill patients.MethodsA prospective, observational, multicenter, cohort study was conducted from January 2010 to March 2011 in five intensive care units in Nord-Pas de Calais, an area from North of France. All patients exhibiting, on ICU admission or during their ICU stay, a hospital-acquired severe sepsis or septic shock could be included in this study. The data collected included patient characteristics on ICU admission and at the onset of severe sepsis or septic shock. The "Candida score" was calculated at the onset of sepsis or shock. The incidence of invasive candidiasis was determined and its relationship with the value of the "Candida score" was studied.ResultsNinety-four patients were studied. When severe sepsis or shock occurred, 44 patients had a score = 2, 29 patients had a score = 3, 17 patients had a score = 4, and 4 patients had a score = 5. Invasive candidiasis was observed in five (5.3%) patients. One patient had candidemia, three patients had peritonitis, and one patient had pleural infection. The rates of invasive candidiasis was 0% in patients with score = 2 or 3, 17.6% in patients with score = 4, and 50% in patients with score = 5 (p < 0.0001).ConclusionsOur results confirm that the "Candida score" is an interesting tool to differentiate among ICU patients who exhibit hospital-acquired severe sepsis or septic shock those would benefit from early antifungal treatment (score > 3) from those for whom invasive candidiasis is highly improbable (score ≤ 3).

Prospective Survey of (1→3)-β- d -Glucan and Its Relationship to Invasive Candidiasis in the Surgical Intensive Care Unit Setting

Non-culture-based diagnostic strategies are needed for diagnosing invasive candidiasis (IC). We evaluated serial serum (1→3)-β-d-glucan (BG) levels in patients in the surgical trauma intensive care unit (SICU) patients with clinical evidence of IC. Serum samples from patients admitted to the SICU for a minimum of 3 days were collected twice weekly and analyzed for BG by using a Fungitell kit with a positive cutoff of ≥ 80 pg/ml. Diagnosis of IC was done using a set of predefined and validated clinical practice-based criteria. A total of 57 patients consented to participate and were enrolled. The median ICU stay was 16 days (range, 3 to 51). A total of 14 of 57 (25%) false positives were observed in the first sample (ICU day 3) and, overall, 73% of the day 3 samples had higher BG levels than subsequent samples. On the date of clinical diagnosis of IC, the sensitivity of a positive BG for identifying invasive candidiasis was 87%, with a 73% specificity. In patients with evidence of IC, the median BG value was significantly higher than those without evidence of IC (171 versus 48 pg/ml, P = 0.02), respectively. In the three patients with proven IC, BG was detected 4 to 8 days prior to diagnosis. BG serum detection may be a useful tool to aid in the early diagnosis of IC in SICU patients, particularly after day 3 and in patients with at least two positive samples drawn several days apart. Elevated BG levels within the first 3 days need to be further characterized.

Serum procalcitonin levels in critically ill patients colonized with Candida spp: new clues for the early recognition of invasive candidiasis?

Invasive candidiasis (IC) outcomes in intensive care units (ICUs) could be improved by the early administration of antifungals. The Candida Score (CS) prediction rule has been proposed for the selection of patients who could develop IC. Procalcitonin (PCT) levels allow prompt identification of sepsis, but their behavior in the setting of IC is unclear. We hypothesize that PCT could be helpful in the early diagnosis of IC in patients with Candida sp. colonization. Prospective observational study. Thirty-six ICUs in Spain, Portugal and France. Every non-neutropenic critically ill patient hospitalized for more than 7 days without concurrent bacterial infection. The CS was calculated weekly. Serums were collected concomitantly. Two hundred twenty PCT levels were measured in 136 patients [neither colonized nor infected (NCNI): n = 73; multifocal colonization (MF): n = 43; MF + IC: n = 20]. Baseline PCT levels were significantly higher in the MF + IC group than in other groups (p = 0.001). In patients with MF, the highest CS value calculated during the patient's stay was the sole independent predictor of IC. The receiver-operating curve analysis showed that the diagnosis values of PCT and CS were comparable (AUROCC = 0.713, and 0.727, respectively). Moreover, PCT increased the positive predictive value of CS from 44.7 to 59.3%. After 7 days of hospitalization, PCT levels in patients with MF who go on to develop IC are higher than in others. Serum PCT could also improve the predictive value of CS. PCT together with CS could therefore be considered for the assessment of IC risk.

Clinical experience of urine D-arabinitol/L-arabinitol ratio in the early diagnosis of invasive candidiasis in paediatric high risk populations

In 2 prospective studies, we previously reported on the early and accurate diagnosis of invasive candidiasis by determining the D-arabinitol/L-arabinitol (DA/LA) ratio in urine in neutropenic children with cancer at the paediatric oncology unit (POU) and in premature infants at the neonatal intensive care unit (NICU) at our hospital. In this retrospective study at the same units, we report how the DA/LA assay was implemented in clinical practice immediately after the prospective study periods. We found that, in the POU, the recommendation of regularly monitoring urine DA/LA ratios in patients at risk and considering antifungal therapy in the case of elevated ratios had been followed. A significant decrease in the incidence of culture positive invasive candidiasis may have been attributed to the introduction of the DA/LA assay. At the NICU, where the DA/LA assay was recommended only as an adjunct to other diagnostic tools, morbidity in invasive candidiasis remained unchanged. While regular monitoring of the urine DA/LA ratio probably facilitates the early detection of invasive candidiasis in paediatric oncology, it remains to be determined if the test can be used in a similar way in neonatal intensive care.

Evaluation of a newly developed down-flow immunoassay for detection of serum mannan antigens in patients with candidaemia

A down-flow immunoassay has been developed to detect serum mannan antigens, and the test was recently marketed as the Unimedi Candida monotest. Using 251 serum samples from 105 patients with candidaemia, a comparison of the Unimedi Candida monotest with the Cand-Tec latex agglutination test and 2 microplate enzyme immunoassay tests (Platelia Candida Ag test and Unimedi Candida) was conducted. One hundred and seventy-five febrile patients without clinical and microbiological evidence of fungal infections and pneumocytosis were examined as controls. The Cand-Tec test had a sensitivity of 38% and a specificity of 82%. The sensitivity and specificity of the Platelia Candida Ag test, the Unimedi Candida and the Unimedi Candida monotest were 53 and 92%, 69 and 89% and 82 and 96%, respectively. The sensitivity of the Unimedi Candida monotest was significantly (P<0.01) higher than that of the Plateria Candida Ag test for diagnosing candidaemia caused by Candida parapsilosis. The beta-D-glucan assay had a high sensitivity of 95%, with a specificity of 84%. Of 74 patients with candidaemia whose sera were available before or on positive blood culture sampling, 29 (39%), 38 (51%) and 48 (65%) patients had antigenemia detected using the Platelia Candida Ag test, the Unimedi Candida and the Unimedi Candida monotest, respectively. The Unimedi Candida monotest seems to be a promising tool for the early diagnosis of invasive candidiasis, because the test was sensitive, simple, rapid (approx. 1 h) and cost-effective.

Early diagnosis of invasive candidiasis with mannan antigenemia and antimannan antibodies

Late treatment of invasive candidiasis (IC) results in severe complications and high mortality. New tools are needed for early diagnosis. We conducted a retrospective study to assess the diagnostic utility of mannan antigenemia (Mn) and antimannan antibodies (anti-Mn) in neutropenic cancer patients at high risk for candidiasis. Twenty-eight patients with IC (based on European Organization for Research and Treatment of Cancer and Mycoses Study Group definitions) and 25 controls were studied. Mn and anti-Mn were positive (≥0.25 ng/mL and ≥5 AU/mL, respectively) in 25/28 (89%) patients with candidiasis and in 4/25 (16%) controls: sensitivity, 89%; specificity, 84%; positive predictive value, 86%; negative predictive value, 88%. In patients with hepatosplenic lesions, assessing Mn/anti-Mn shortened the median time of diagnosis of candidiasis when compared with imaging (9 versus 25 days after fever onset as first sign of infection; P < 0.001). Candidiasis was diagnosed before neutrophil recovery in 78% and 11% of cases with Mn/anti-Mn and radiology, respectively ( P < 0.001). Mn and anti-Mn may be useful for early noninvasive diagnosis of IC.

Performance des Candida‐Mannan‐Antigennachweises bei Patienten mit Fungämien

ZusammenfassungZur Diagnostik invasiver Candidosen steht seit einigen Jahren der kommerziell erhältliche Platelia®Candida Mannan Antigen Enzymimmunoassay (Candida EIA) zur Verfügung. Wir evaluierten den Candida EIA an Patienten mit nachgewiesener Fungämie durch Sproßpilze, von denen zumindest eine Serumprobe zur Verfügung stand. In die Studie eingeschlossen wurden 59 Patienten mit 121 Serumproben, von denen 61 verschiedene Sproßpilz‐Isolate aus Blutkulturen angezüchtet wurden. Der Candida EIA war bei 43 von 59 Fungämie‐Patienten positiv (n = 35) oder grenzwertig (n = 8), woraus eine Sensitivität von 73% resultierte. Für die einzelnen Sproßpilz‐Arten ergaben sich folgende Positiv‐Raten: Candida albicans 30 von 39 (77%), Candida glabrata 7 von 11 (64%), Candida parapsilosis 1 von 3, Candida tropicalis 2 von 2, Candida kefyr 2 von 2, Candida lipolytica 0 von 1, Candida lusitaniae 1 von 1, Candida krusei 1 grenzwertig von 1, Saccharomyces cerevisiae 1 von 1. Bei 6 Patienten war der zeitliche Antigen‐Verlauf auswertbar. In 3 Fällen war der Antigennachweis 3 bis 4 Tage vor dem Tag der Blutkulturentnahme positiv, in einem Fall am selben Tag und in 2 Fällen 2 bzw. 5 Tage danach.SchlußfolgerungenDer Candida EIA war zur Erfassung von Fungämien durch die häufigsten fakultativ pathogenen Sproßpilz‐Arten geeignet. Der Test war bei etwa der Hälfte der Patienten vor einer Blutkultur positiv und trug damit zur frühzeitigen Diagnosestellung einer invasiven Candidose bei.

Early diagnosis of invasive candidiasis and rapid evaluation of antifungal therapy by combined use of conventional chromogenic limulus test and a newly developed endotoxin specific assay.

Since beta-1,3-glucan is a common component of fungal cell wall, its detection might be useful in diagnosing invasive candidiasis. Not only endotoxin but beta-1,3-glucan activates proclotting enzyme contained in a conventional chromogenic limulus test (CCLT). Endotoxin activates this enzyme through factor C, while the beta-1,3-glucan activates through factor G. Since endotoxin specific test (EST) contains factor C, endotoxin would be quantified. By subtracting EST value from CCLT value, beta-1,3-glucan would be quantified. We named this value Fungal Index (FI), and examined if it actually reflects the candidal infection. Ninety-two patients were tested for CCLT and EST prospectively. FI increased significantly in candidal infection (p less than 0.05) but remained low in GNR infection. Moreover, FI increased proportionally to the severity of candidal infection. Elevated FI decreased when antifungal therapy was successful. Thus FI was a useful index not only in the diagnosis of invasive candidiasis but also in the evaluation of antifungal therapy.

Early diagnosis of invasive candidiasis in leukemia : Evaluation of D- arabinitol in serum.

Forty-two healthy controls and 50 patients with leukemia were studied for serum D-arabinitol determined by enzymatic fluorometric method. Values of D-arabinitol ranged from 0 to 13.3μmol/l with a mean of 6.5 for healthy controls and from 0 to 29.6μmol/l with a mean of 7.7 for symptomless leukemia patients. Patients suspected to have invasive candidiasis showed a significantly high serum D-arabinitol, with a mean of 36.7 ranging from 16.2 to 69.6μmol/l. However, serum D-arabinitol decreased promptly in response to administration of antifungal agents. Our results suggest that determination of serum D-arabinitol may be useful in aiding diagnosis of invasive candidiasis prior to the antifungal therapy, and also in evaluation the patient's response to the antifungal agents.